I always wear a helmet when I ride my bike.
Also, when I walk around the city or drive a car, cause the risk of head injury is comparable to riding a bike, it just makes sense.
Most accidents occur at home, so when I'm there, I wear 2 helmets.
It's not just about yourself, OP. You gotta think about your wife, girlfriend, husband or boyfriend, too (not judging btw).
When you're a vegetable you can't support them anymore and their lover is forced to get a job, do you really want that?